Abstract
Present-day speculation on extraterrestrial intelligence, taking its cue from a number of programmes currently "listening" for electro-magnetic signals from space, have a prehistory dating back to the immediate aftermath of the Copernican Revolution. Throughout the centuries of the Early Modern Period, it was not only theological but also more or less secular philosophical concerns that informed the hopes and the fears that writers of all stripes associated with the tentative notion that "We are not alone." It was not until the "Romantic" period, around 1800, that a reaction set in: as Goethe put it, there is also a universe within us-one worthier of our attention than the cosmos